1. Field of the Invention
This invention relates to the process of making lead-free projectiles such as bullets and shot by the technique of liquid metal infiltration.
2. Brief Description of the Art
Liquid metal infiltration is a well known technique for making certain metal objects where a porous preform made of one or more constituents having a relatively high melting temperature is infiltrated by a molten metal or alloy whose melting point is less than that of the constituents making up the porous preform. See Claus G. Goetzek, Infiltration, Metals Handbook Ninth edition, Vol. 7, Powders Metallurgy, pages 551-566 (1984); for a detailed description of this operation.
Liquid metal infiltration has been used to make a wide variety of metal articles of manufacturing, including electrical contacts and electrodes, rocket nozzles, jet engine components, tools, mechanical parts and bearings. It is believed this technique has never been used to make projectiles, specifically, lead-free projectiles that have similar ballistic performance characteristics similar to those of lead-type projectiles.